Sealing leakage problem in chemical process centrifugal pumps
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This post was last edited by lrtlrtlrt on 2018-8-21 07:55. Our company has a chemical centrifugal pump, which is one of the most common types used in chemical plants. The fluid handled by this pump is dimethyl terephthalate; its head is 20 M, power consumption is 2.2 kW, rotation speed is 1450 rpm, flow rate is 6 M3/h, and the maximum operating pressure is 0.2 MPa. We replaced the Bergman 59U-50 seal as well as the shaft sleeve. The O-rings of the seal are made of PTFE material (brand new). The fit between the stationary and rotating rings was tightened by an additional 1 mm. After reinstallation, no leakage occurred when the pump was filled with fluid. However, there was slight leakage during the first 3 minutes of operation; once the pump was running properly (with pressure and flow rates meeting the requirements), almost no leakage was observed at the seal area. Could this situation be due to problems with the stationary and rotating rings of the seal? Is the fit between the rotating ring and the stationary ring not tight enough? Is it still a problem with the materials of the rotating and stationary rings (graphite silicon carbide is being used, and no cracks or defects could be seen with the naked eye in the friction pairs of the new seal)?
Then the mechanical seals you use must be bulk-supplied ones. After all that you’ve said, the conclusion is that everything is normal; I’m not sure what you want to ask
It’s normal for there to be some issues in the first three minutes; it might be that the pump hasn’t reached its operating conditions. In addition to the pressure and flow rates you mentioned, it’s also worth checking the pump’s operating temperature
Is this a condition present from birth? Will it be available the day after tomorrow instead? If it’s available the day after tomorrow, check whether during installation the sealing areas of the pump’s body and rotor, as well as the gaps between them, have been corroded, and whether everything was installed properly. If it is congenital, it is necessary to check whether the operating procedures meet the requirements.
There is still leakage; it continues even after the pump is turned off. There’s about one drop per 5 minutes. No matter whether I replace the mechanical seal with a Bergman one or another type, the situation remains the same
There is still leakage; it continues even after the pump is turned off – about one drop per 5 minutes. The leakage is much less when the pump is running, but there’s still a slight amount of it. No matter whether I replace the mechanical seal with a Bergman one or another type, the situation remains the same
Graphite is not very stable, and slight deformation of the sealing surface may occur during storage. It can perform adaptive repair by running; it’s normal for this phenomenon to occur
Running-in period: lol:lol:lol:lol:lol:lol:lol
Switch to antimony-doped graphite for silicon carbide, or silicon carbide for silicon carbide!